Blood sugar, also known as blood glucose, is produced by the body from the food we eat. Food is broken down in the intestines and converted into blood sugar, which is energy fuel for the body. Blood sugar is absorbed into the bloodstream and sent throughout the entire body. Individual cells use this energy to keep the body functioning properly. If blood sugar levels are too high, various health problems can occur such as hyperglycaemia and diabetes. Foods which lower blood sugar can help manage these conditions and keep the blood sugar levels in a normal range.
Diets which include 50g or more of fibre a day can help lower blood sugar. The reason lies in the way fibre behaves in the digestive tract. Fibre reduces the rate of digestion, and fibre-rich foods take longer to break down. This means that the resulting sugars are absorbed slowly, which keeps overall blood sugar lower. Some foods which are high in fibre are beans and sweet potatoes. Whole-grain breads and cereals made with bran are also good fibre sources.
Nuts have a positive effect on blood sugar levels by lowering insulin resistance. Insulin is the hormone that directly affects the ability of cells to absorb sugar. Nuts provide fuel and contain properties which help the body use insulin. Nuts are rich in unsaturated fats, which are considered "good fats." They digest slowly, helping with blood sugar absorption. Recommended nuts include almonds, peanuts, walnuts, cashews and macadamia nuts.
Many fruits are known to help lower blood sugar levels. Lemons are on the list and are high in vitamin C, limonene and rutin, which help keep overall blood sugar levels low. Cherries, which contain antioxidants and high levels of soluble fibre, are known to help increase the amount of insulin created by the body. Avocados are actually considered a fruit and are known to raise insulin sensitivity, helping cells process blood sugars.
Some spices are included on the list of blood sugar lowering foods. Cinnamon can be added to many other foods for flavour, and it has the added benefit of keeping blood sugar low. It contains natural compounds that act much like insulin and assist with blood sugar processing. Cinnamon has high levels of fibre and contains magnesium, a mineral also known for controlling blood sugar. Raw garlic is another helpful spice. It raises the production of insulin while increasing insulin sensitivity.
Other food sources which lower blood sugar levels are onions, flaxseed, vinegar and black tea. Onions contain high levels of sulphur and flavonoid, which are antioxidants that act to reduce blood sugar. Flaxseed has both high fibre and healthy fat, which is known to reduce blood sugar levels. It also contains several other helpful minerals such as thiamine, magnesium, copper and phosphorus. Vinegar, when added to highly starchy meals, reduces blood sugar and lowers the spike of insulin that happens after such a meal. Studies by King's College, London, in 2007 found that black tea lowers blood sugar and also helps increase insulin levels.